We can deploy the SharePoint Add-ins to FOLLOWING two places.
SharePoint Add-in Catalog: We can UPLOAD the SharePoint Add-in to organization's add-in catalog site. An Add-catalog, is nothing but a special collection in SharePoint online which contains a special type of document library that is used to upload and store app package files. Once you add the add-in to add-in catalog, the ad-in will be available to all SharePoint site COLLECTIONS. You can check a SharePoint video tutorial on: Video Tutorial Create and Deploy SharePoint Hosted Add-in using Visual STUDIO 2015

To the Office Store: We can also deploy SharePoint Add-ins to Office store. Microsoft has a Seller Dashboard to help you sell add-ins through the Office Store.
After you deploy the add-in in either way, it's available for installation on the add an add-in page of SharePoint websites. 

We can deploy the SharePoint Add-ins to following two places.
SharePoint Add-in Catalog: We can upload the SharePoint Add-in to organization's add-in catalog site. An Add-catalog, is nothing but a special collection in SharePoint online which contains a special type of document library that is used to upload and store app package files. Once you add the add-in to add-in catalog, the ad-in will be available to all SharePoint site collections. You can check a SharePoint video tutorial on: Video Tutorial Create and Deploy SharePoint Hosted Add-in using Visual Studio 2015

To the Office Store: We can also deploy SharePoint Add-ins to Office store. Microsoft has a Seller Dashboard to help you sell add-ins through the Office Store.
After you deploy the add-in in either way, it's available for installation on the add an add-in page of SharePoint websites.